TRPV4 Initiates Ventilator Induced Lung Injury

TRPV4 引发呼吸机引起的肺损伤

• 批准号: 7653156
• 负责人: JAMES Courtney PARKER
• 金额: $ 35.52万
• 依托单位: UNIVERSITY OF SOUTH ALABAMA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7653156
• 关键词: Acute Lung Injury; Adult Respiratory Distress Syndrome; Aftercare; Agonist; Alveolar; Alveolar Macrophages; Blood Coagulation Disorders; Blood capillaries; Breathing; Calcium; Cations; Cells; Clinical Research; Clinical Trials; Coagulation Process; Coculture Techniques; Cyclic AMP-Dependent Protein Kinases; Data; Endothelial Cells; Endothelium; Environmental air flow; Epithelial; Epithelial Cells; Epithelium; F2R gene; Fluorescence Microscopy; Genotype; Human; Infusion procedures; Intervention; Ion Channel; Laboratories; Link; Lung; Measures; Mechanical ventilation; Mechanics; Mediating; Mus; Neurons; PAR-2 Receptor; Patients; Peptide Hydrolases; Peptides; Permeability; Phorbol; Phorbols; Plasma; Plasma Proteins; Plasminogen Activator Inhibitor 1; Protein C; Proteinase-Activated Receptors; Pulmonary Edema; Reporting; Research; Rest; Secondary to; Sepsis; Stretching; Testing; Thrombin; Tidal Volume; Trauma; Trypsin; Vanilloid; Vascular Permeabilities; Ventilator-induced lung injury; activated Protein C; capillary; electric impedance; in vivo; inhibitor/antagonist; lung injury; macrophage; monolayer; mortality; patch clamp; pressure; prevent; receptor; response

After some 40 years of research and numerous failed clinical trials, only two interventions have been shown to significantly reduce the high mortality rate of the acute respiratory distress syndrome (ARDS), a reduction of tidal volume during mechanical ventilation (22%), and infusion of activated protein C (19%). These clinical studies indicate that coagulation activation renders the lung exquisitelv sensitive to stretch because the injurious lung distention producing a 22% increase in ARDS fatalities is half that in resting tidal breathing. We recentty reported that experimental Ventilator Induced Lung Injury was prevented in mice by deletion of the calcium-permeable stretch-activated transient receptor potential vanilloid-4 (TRPV4) ion channel. Recent studies indicate that the proteinase activated receptor-2 (PAR2) associates with the TRPV4 channel in neurons and greatly amplifies the TRPV4 induced calcium increase. We show (Preliminary Data) that lung epithelial cell monolayers co-cultured with alveolar macrophages activated with trypsin (PAR2), thrombin (PAR1, 3, 4) or the TRPV4 agonist, 4alpha-phoroot 12,13--didecanoate (4a-PDD) given separately actually decreased monolayer permeability, but that pre-treatment with either trypsin or thrombin followed by 4a-PDD produced a sustained permeability increase. We Hvpothesize: that coagulation induced proteases and TRPV4 induced alveolar macrophage release of proteases that activate PAR2 and PAR1, 3, and 4 which then amplify the mechanogated TRPV4 response in epithelial and endothelial cells sufficiently to cause increased lung vascular permeability. We propose these Specific Aims: 1) Test the hypotheses that: PAR1 and PAR2 activation peptides followed by 4a-PDD amplify the TRPV4 mediated calcium influx in alveolar macrophages and alveolar epithelial cells measured using whole cell patch clamp and fluorescence microscopy; and that the PAR amplification is reduced by inhibitors of PLC~, PKA, and PKC. 2) Test the hypothesis that PAR1 and PAR2 activation peptides followed by 4a-PDD increases alveolar epithelial monolayer permeability using electric cell-substrate impedance sensing, and that lung PAR1 and PAR2 activation peptidesincrease lung vascular permeability in TRPV4+/+ mice ventilated with high airway pressures but not in TRPV4-/- mice, or either genotype ventilated with low airway pressures

经过大约40年的研究和无数失败的临床试验，只有两种干预措施被 可显著降低急性呼吸窘迫综合征的高死亡率 (ARDS)，机械通气时潮气量减少(22%)，以及输注活化的 蛋白C(19%)。这些临床研究表明，凝血激活使肺 Exquisitelv对拉伸敏感，因为损害性肺扩张导致22%的 急性呼吸窘迫综合征的死亡人数是静息潮气呼吸的一半。我们最近报道了实验性呼吸机 钙通透性牵张激活基因缺失预防小鼠肺损伤 瞬时受体电位香草酸-4(TRPV4)离子通道。最近的研究表明， 蛋白水解酶激活受体-2(PAR2)与神经元中的TRPV4通道密切相关。 增强TRPV4诱导的钙升高。我们显示(初步数据)肺上皮细胞 用胰酶(PAR2)、凝血酶(PAR1、3、 4)或TRPV4激动剂，4α-磷酸12，13-十二酸(4a-PDD)实际上单独给出 降低单层通透性，但用胰酶或凝血酶预处理后 4A-PDD可使通透性持续增加。我们知道：这种凝结导致了 蛋白水解酶和TRPV4诱导肺泡巨噬细胞释放激活PAR2的蛋白酶 和PAR1、3和4，然后放大上皮细胞和 内皮细胞足以引起肺血管通透性增加。我们提出这些建议 具体目标：1)检验假设：PAR1和PAR2激活肽后面跟着4a-PDD 放大TRPV4介导的肺泡巨噬细胞和肺泡上皮细胞钙内流 用全细胞膜片钳和荧光显微镜测量；PAR扩增 被PLC~、PKA和PKC的抑制剂降低。2)检验PAR1和PAR2的假设 激活肽与4a-PDD联合应用增加肺泡上皮单层通透性 细胞-底物阻抗感应，肺PAR1和PAR2激活肽增加 TRPV4+/+小鼠在高气道压力下的肺血管通透性 TRPV4-/-小鼠，或任何一种基因型的低气道压呼吸